Dual Power Pin Connector Assembly For A MIG Welding Machine

ABSTRACT

A dual power pin connector assembly for connecting both a MIG welding gun and a spoolgun to a welding machine. The dual power pin connector is comprised of a busbar portion that electrically and mechanically couples the positive output terminal of the welding machine power supply to a wire drive for the MIG welding gun. The connector is further comprised of an integral quick release assembly/clamping portion that electrically and mechanically connects the positive power supply terminal to a power supply cable for the spoolgun. The clamping portion receives and retains a power pin coupled to one end of the spoolgun power cable in a receptacle that is manually tightened and loosened.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/038,550, which was filed on Feb. 27, 2008 and entitled “DUALPOWER PIN CONNECTOR ASSEMBLY FOR A MIG WELDING MACHINE,” which isincorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

The present invention relates generally to welding-type systems and,more particularly, to an apparatus that provides welding-type power to aMIG welding gun while also providing a quick and easy means forsupplying welding-type power to a spoolgun.

There are many welding-type systems used for a variety of applications.The term “welding-type systems”, as used herein, includes arc weldingsystems, plasma cutting systems, and induction heating systems.Accordingly, the term “welding-type power”, as used herein, may refer towelding, plasma cutting, or induction heating power. One primarycomponent of all welding-type systems is a power supply that deliversconditioned welding-type power to perform a specific welding-typeprocess.

Some welding-type applications, such as steel arc welding, utilize amotor driven wire feeder, or wire drive, that delivers a consumable wireelectrode to a welding gun, or torch, to perform a desired welding-typeprocess, such as MIG welding. One common type of wire drive is a voltagesensing wire drive. Voltage sensing wire drives are typically connected,via a cable, to the positive terminal of a welding-type power supply.The wire drive is further coupled to the consumable wire electrode. Thenegative terminal of the power supply is connected to a workpiece suchthat when the positive wire electrode is close enough to the negativework piece to create an arc, a desired welding process occurs.Generally, voltage sensing wire drives become active when the voltageand/or current provided by an associated power supply increases above athreshold value. In this regard, the wire drive does not typicallyreceive control signals or communicate with the power supply.

In other welding-type applications, for example, MIG welding with aconsumable aluminum wire electrode, the standard wire drive may not besuitable. For instance, when MIG welding with aluminum wire, specialequipment adapted specifically to handle the softer wire must be used.Aluminum wire electrodes can easily be damaged by equipment otherwiseacceptable for steel wire electrodes.

One type of equipment suitable for aluminum welding is known as aspoolgun. The spoolgun is a self-contained welding gun equipped to feeda soft wire electrode from a small spool mounted directly on the gun.The distance from the wire to the contact tip is very short, usuallyless than twelve inches and therefore is better able to feed the softaluminum wire electrode without problems. A spoolgun power supply cable,typically up to 50 feet in length, is run between the welding powersupply and the spoolgun.

Users that switch frequently between steel and aluminum welding oftenfind it convenient and cost-effective to purchase and use a singlewelding machine that is able to drive both a spool gun and a standardMIG gun. Some existing welding machines are configured such that a MIGgun and a spoolgun may be connected to the welding machine at the sametime.

Referring now to FIG. 1, one such prior art welding machine 10 is shown.The welding machine 10 is powered by a switched or inverter-based powersupply 12 contained within a housing 14. A pair of welding-power outputterminals 16, 18 extend from the housing 14. The welding machine 10further includes a power input connection (not shown) that receives ACpower, such as that received from a standard power receptacle. As isknown in the art, the supply power is rectified and conditioned, therebyconverting the incoming AC power to a DC welding-type power.

As shown, the welding machine 10 is connected to a standard MIG weldinggun, or torch, 20 that delivers a consumable wire electrode 22 toeffectuate a welding-type operation. The wire electrode 22 iselectrically connected to the positive welding power terminal 16, asdescribed in greater detail below, while a work piece 24, upon which awelding-type operation will occur, is electrically connected to thenegative welding power output terminal 18 via a clamp 40 and a groundingcable 38 extending therebetween.

When the positively charged wire electrode 22 either makes directcontact with the negatively charged workpiece 24 or the gap therebetweenis sufficiently narrow, an arc is created between the wire 22 andworkpiece 24, resulting in a completed circuit and causing awelding-type process to occur. In one welding-type process, i.e., arcwelding, the resulting electrical current and voltage cause the wireelectrode 22 and a portion of the workpiece 24 to become superheated andmelt. The melted electrode 22 and workpiece 24 mix together and thencool to become permanently bonded together.

The welding machine 10 is further comprised of an automatic wire drive26 that feeds the consumable wire electrode 22 from a supply spool 28 tothe welding gun 20 when a trigger 21 is depressed. In the illustratedembodiment, the welding power output terminals 16, 18 and wire drive 26are situated in close proximity to each other within a compartment 30 ofthe welding machine 10. However, other configurations exist where thewire drive 26 is located external to the welding machine 10.

The wire drive 26 receives the welding-type power via an electricallyconducting cable 32 connected between the positive terminal 16 and thewire drive 26. The consumable wire electrode 22 becomes energized whenpassing through a power pin 31 (see FIG. 2) that is electrically coupledto the wire drive 26. The wire electrode 22 is then run inside ashielding gas hose 33 to the MIG gun 20. The hose 33, electrode 22 and acontrol cable 34 may be integrated into a single sheathed assembly 36extending between the welding machine 10 and the gun 20. The groundingcable 38 is connected to the workpiece 24 via the grounding clamp 40 andthe negative welding power terminal 18 via an electrical connector toprovide a return path for the electrical current.

Still referring to FIG. 1, a spoolgun 42 may be connected to the weldingmachine 10 at the same time as the MIG gun 20. Connections between thespoolgun 42 and the welding machine 10 include a separate control cable44, shielding gas hose 46, and power supply cable 48. Because thespoolgun 42 does not use the consumable wire electrode 22 supplied bywire drive 26, the separate power supply cable 48 is needed to supplythe welding-type power from the power supply 12. In operation, aseparate spool of consumable wire electrode (not shown) stored withinthe spoolgun 42 is energized and supplied to the workpiece 24 toeffectuate a welding-type process.

To connect the spoolgun 42 to the power supply 12, the positive weldingpower terminal 16 must be accessed by opening the welding machine 10 toreveal the compartment 30. A wrench or similar tool is typically used toloosen a nut 50 tightened onto the terminal 16. One end of the spoolgunpower cable 48, typically provided with a suitable electrical connector17 is then fixedly fastened to the terminal 16 by tightening the nut 50against the connector 17 as shown. The aforementioned cable 32 for thewire drive 26 is also secured to the positive output terminal 16 in asimilar manner.

To disconnect the spoolgun 42 from the welding machine 10, theaforementioned process is essentially reversed. A tool is needed toloosen the nut 50 from the terminal 16 and as a result it is commonpractice to leave the spoolgun 42 connected to the welding machine 10with the power cable 48 coiled up, even when not needed.

It is labor intensive and time consuming to add or remove a spoolgun 42in this manner. Further, repeated tightening and loosening of the nut 50may cause operational problems. For example, the nut 50 may not betightened sufficiently and work itself loose over time. Still further,tools, such as wrenches and the like, are easily misplaced or lostresulting in time wasted while looking for a suitable tool to loosen thenut 50 from the power terminal 16. For these reasons, repeatedlyconnecting and disconnecting the spoolgun power supply cable 48 directlyto the positive welding terminal 16 is not a desirable practice in thewelding industry. Instead, many users leave the spoolgun 42semi-permanently connected to the welding machine 10, even when notplanning to use it, rather than disconnecting the spoolgun 42.

Even this practice has drawbacks, however. When a spoolgun 42 is leftconnected to a welding machine 10, the spoolgun power supply cable 48 istypically coiled up and stored, along with the spoolgun 42 alongside theexterior of the welding machine 10. The spoolgun 42 and power supplycable 48 are thus exposed and unprotected against environmentalconditions, accidental contact with other equipment, or simply beingdropped on the ground.

Therefore, a need exists for an improved apparatus and method forquickly and easily connecting and disconnecting a spoolgun to a standardwelding machine without the need for tools.

Accordingly, attempts have been made to design various quick connect andrelease cables for spool guns. Such cables provide a quick and easy wayto connect and/or disconnect a spoolgun and its associated power supplycable and gas hose. A number of prior art systems require specialconnectors and unique cable assemblies that cannot be used on existingwelding machines.

One such prior art quick release connector mechanism is disclosed inU.S. Pat. No. 7,208,699. However, one drawback to this and similar priorart devices is that these mechanisms will not work on existing spoolgunsor welding machines without substantial modifications, if at all.

Therefore, it would be desirable to have a quick-connect device for awelding machine such that a spoolgun or other welding implement may beadded or removed from a welding machine without the need for tools andwithout the need to retrofit an existing welding machine.

BRIEF SUMMARY OF THE INVENTION

The present invention overcomes the aforementioned drawbacks with aconnector that, in one embodiment, may be added to an existing weldingmachine with only minor modifications. Specifically and in accordancewith one aspect of the present invention, a dual power pin connector isprovided that electrically couples both a standard MIG welding gun and astandard spoolgun to a welding-type power supply. The connector iscomprised of an electrically conductive busbar assembly having a firstend fixedly connected to the positive welding power terminal and asecond end fixedly connected to the wire drive of a welding machine. Theconnector is further comprised of an electrically conductive clampingassembly coupled to the busbar assembly. The clamping assembly can betightened by hand to secure one end of a spoolgun power supply cable.

The connector provides welding power to the MIG welding gun through aconductive path including the busbar, the wire drive, a power pin, and aconsumable wire electrode energized by contact with the power pin anddelivered to the MIG gun. The connector also provides welding power tothe spoolgun through a conductive path including the busbar, theclamping mechanism, a power pin, and the spoolgun power supply cable.

In accordance with another aspect of the present invention, a weldingsystem is disclosed that includes a power source having a pair of outputterminals, a first welding implement such as a MIG gun, a second weldingimplement such as a spoolgun, a wire drive that provides a consumablewelding electrode to the first welding implement, and a dual power pinconnector that connects the power source to both the wire drive and thesecond welding implement. The dual power pin connector has a firstreceptacle to electrically connect the power source to the wire drive(and thus the first welding implement). The dual power pin connectoralso has a second receptacle to electrically connect the power source tothe second welding implement at the same time as the first implement.

In accordance with yet another aspect of the present invention, awelding machine having a wire drive comprised of an integral dual powerpin connector assembly is disclosed. The integrated wire drive includesa quick release clamping assembly to simultaneously connect the powerpin of a MIG gun and the power pin of a spoolgun to the wire drive. Aconductive cable provides welding power from the power supply to thewire drive which in turn provides the welding power to the MIG gun via aconsumable wire electrode and to the spoolgun via a power supply cable.

In accordance with still another aspect of the present invention, amethod of quickly connecting or disconnecting a spoolgun to a weldingmachine is provided. The method includes providing a conductive dualpower pin connector having a clamping assembly, securing one end of theconnector to a welding power terminal, securing a second end of theconnector to a wire drive that feeds a consumable wire electrode to aMIG gun, and securing one end of a spoolgun power supply cable to theconnector via the clamping assembly.

Various other features of the present invention will be made apparentfrom the following detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will hereafter be described with reference to theaccompanying drawings, wherein like reference numerals denote likeelements, and:

FIG. 1 is an isometric view of a MIG welding gun and a spoolgunconnected to a prior-art welding machine;

FIG. 2 is an isometric view of a dual power pin connector assemblyconstructed in accordance with one aspect of the present inventioncoupling a positive power supply terminal to a wire drive and a spoolgunpower pin;

FIG. 3 is an isometric view of the body of the dual power pin connectorassembly of FIG. 2;

FIG. 4 is a side view of the installed dual power pin connector assemblycorresponding to FIG. 2;

FIG. 5 is a side view corresponding to FIG. 4 and showing the spoolgunpower pin removed from the dual power pin connector; and

FIG. 6 is an isometric view of a dual power pin connector assemblyintegrated into a wire drive and constructed in accordance with anotheraspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While still referring to several of the components of the weldingmachine 10 of FIG. 1, a dual power-pin connector assembly, or powerbridge, 100 is shown in FIGS. 2-5 that enables at least two weldingimplements to be connected to the welding machine 10 at the same time.The dual power-pin connector 100 is cast or machined from anelectrically conductive material such as steel, copper, or the like. Inone embodiment, the connector 100 electrically couples the positivewelding power terminal 16 to a first welding implement, for example, MIGwelding gun 20, via a conductive path that includes the connector 100,the automatic wire drive or feeder 26, the power pin 31 and theconsumable wire electrode 22. The connector 100 also electricallycouples the terminal 16 to a second welding implement, for examplespoolgun 42, via a conductive path that includes the connector 100,spoolgun power pin 54 and spoolgun power supply cable 48.

According to the embodiment shown, the dual power pin connector 100includes an electrically conductive elongated plate assembly, or busbarportion, 103 configured to extend between the positive welding poweroutput terminal 16 and the wire drive 26. The busbar portion 103 isformed with an elongated plate, or busbar, 104 with a first securing, ormounting, leg 105 extending from one end of the busbar 104 and a secondsecuring, or mounting, leg 107 extending away from an opposing end ofthe busbar 104. Both securing legs 105, 107 have holes 109, 111 formedtherein to fixedly secure the busbar portion 103 with appropriatefastening means. For example, the first securing leg 105 is attached tothe wire drive 26 with a bolt 113, while the second securing leg 107 issecured onto the positive welding output terminal 16 with a nut 50. Thebusbar portion 103 provides the aforementioned conductive path forelectricity to flow from the positive welding terminal 16 to the wiredrive 26, and therefore MIG welding gun 20. The connector 100 thusreplaces the prior art conductive cable 32 used in the welding machine10 and shown in FIG. 1.

The connector 100 is further comprised of an electrically conductingquick release assembly 101 extending outwardly from the busbar portion103. The quick release assembly 101 includes a power pin receivingassembly 140 that receives the power pin 54 of a second weldingimplement, for example, spoolgun 42.

As shown, the power pin receiving assembly 140 is comprised of aguide/support ring 139 and a clamping ring or clamp 119. The clampingring 119 includes a retaining passage 135 that receives a portion of thespoolgun power pin 54. The clamping ring 119 further includes a meansfor securely retaining the power pin 54 within the passage described ingreater detail below. The guide/support ring 139, which also includes apassage 141, acts to guide the spoolgun power pin 54 into the passage135 of the clamping ring 119. Additionally, the ring 139 acts to retainthe power pin 54 within the clamping ring 119 by providing additionalsupport against pulling forces applied to the spoolgun power supplycable 48.

Other embodiments of the connector 100 still considered within the scopeof the invention may have alternative types of quick release connectorsrather than the guide ring 139 and clamping ring 119 shown. Theseconnectors include, but are not limited to, twist lock fittings such asthose manufactured by Dinse, GmbH and a lug style fitting. With a twistlock fitting, a female connector coupled to the connector 100 wouldreceive a male connector coupled to the spoolgun power supply cable 48.

To install the dual power pin connector 100 into a standard weldingmachine 10 as shown in FIGS. 2, 4 and 5, the cable 32 that normallyprovides welding power to the wire drive 26 must be removed. The firstleg 105 of the busbar portion 103 is fixedly secured to the wire drive26 by inserting the bolt 113 through the bolt hole 109 and into athreaded passage 115 of the wire drive 26. The second leg 107 of thebusbar portion 103 is fixedly secured onto the positive output powerterminal 16. The connector 100 is placed such that power terminal 16extends through the bolt hole 111 in the leg 107. The retaining nut 50is then tightened to fixedly secure the second leg 107 to the positivewelding terminal 16. Both the bolt 113 and the nut 50 are tightened suchthat the connector 100 will be securely retained indefinitely.

Once the connector 100 is installed as described above and after thewelding machine 10 is powered up, the dual power pin connector 100provides welding power to the MIG gun 20. Conditioned electricityproduced by the welding power supply 12 flows from the positive terminal16 to the gun 20 via a conductive path comprised of the busbar portion103 of the connector 100, wire drive 26, MIG gun power pin 31 andconsumable wire electrode 22. Wire electrode 22 is run through a bore 23in the power pin 31 (see FIG. 6) and becomes energized through contactwith the energized power pin 31.

In order to use the dual power pin connector 100 to provide weldingpower to the spoolgun 42, the spoolgun power pin 54, connected tospoolgun power cable 48, must be secured within the power pin receivingassembly 140. A manually operated clamping ring 119 is provided toreleasably secure the spoolgun power pin 54. The spoolgun power pin 54is inserted through the passage 141 of the guide/support ring 139 andinto the passage 135 formed by the clamping ring 119. The power pin 54is inserted until an annular shoulder 56 of the power pin 54 abuts oneside 142 of the quick release assembly 101. Thereafter, the clampingring 119 is compressed and clamped against the power pin 54 by turningthe knob 129 creating a friction fit sufficient to retain the pin 54within the receiving assembly 140.

According to the embodiment shown, the clamping ring 119 is compressibledue to the presence of a gap 121 in the ring 119 extending outwardlyfrom the passage 135. Two axially aligned passages are formed in theclamping ring 119 on opposite sides of the gap 121: a smooth passage 123and a threaded passage 125. A threaded rod 127 coupled to the knob 129extends completely through the smooth passage 123 and into threadedengagement with the threaded passage 125. Turning the knob 129 in afirst, i.e., clockwise, direction drives the rod 127 further into thethreaded passage 125, causing opposed faces 131, 133 of the gap 121 tobecome drawn together. This, in effect, diminishes the gap 121 andtightens the clamping ring 119 until the spoolgun power pin 54 is fullysecured and retained therein.

The spoolgun 42 is thus electrically coupled to the positive outputterminal 16 via a conductive path that includes the connector 100, viathe busbar portion 103 and quick release assembly 101, spoolgun powerpin 54 and spoolgun power supply cable 48.

To manually release the power cable 48, the knob 129 is turned in areverse, i.e., counterclockwise, direction. Turning the knob 129 in sucha direction withdraws the rod 127 from the threaded passage 125, causingthe gap 121 to increase and relieving the clamping pressure against thespoolgun power pin 54. As shown in FIG. 5, the power pin 54 may then bewithdrawn from the dual power pin connector 100 and through the opening117 of the welding machine 10. The spoolgun gas supply hose 46 andcontrol cable 44 are also disconnected by hand.

As such, the dual power pin connector 100 provides welding-type power toboth the welding gun 20 (via contact with wire drive 26) and thespoolgun 42. The connector 100 further provides a quick, easy andtool-free means for connecting and disconnecting the spoolgun 42.

Referring now also to FIG. 6, another embodiment of a dual power pinconnector 200 is shown. In this embodiment, the power pin connector 200is integrated into the wire drive 226. A wire drive 226 having such anintegrated power pin connector 200 may be installed within a welder suchas the welding machine 10 of FIG. 1.

The function and operation of the integrated dual power pin connector200 is similar to the connector 100 shown in FIGS. 2-5 and describedabove. However, the power pin connector 200 of this embodiment is notremovable from the wire drive 226. Additionally, the connector 200 doesnot provide a conductive path for welding-type power between thepositive welding output terminal 16 and the wire drive 226. Instead, acable, such as the cable 32 shown in FIG. 1, or other conductive meansis needed to electrically couple the power terminal 16 to the wire drive226.

The power pin connector 200 is comprised of a clamping assembly 219having two receptacles 234, 235 and a slot 221 extending between them.The connector 200 further includes two guiding support rings—a firstring 238 for the power pin 31 of a MIG welding gun 20 and a second ring239 for the power pin 54 of a spoolgun 42. The rings 238, 239 assist insecuring and retaining the pins 31, 54 as previously described withrespect to the connector 100 of the first embodiment.

The receptacles 234, 235 receive and retain one end of the power pins31, 54 respectively. A threaded rod 227 coupled to a knob 229 extendsthrough a smooth passage 223, through the slot 221, and into a threadedpassage 225 formed in the wire drive 226. As with the connector 100 ofFIGS. 2-5, when the knob 229 is turned, the rod 227 is driven furtherinto the threaded passage 225 causing the gap formed by slot 221 todiminish. The clamping assembly 219 thus becomes forcibly pressedagainst the power pins 31, 54 to releasably secure them within thereceptacles 234, 235.

The power pins 31, 54 may be removed from the dual power pin connector200 by turning the knob 229 in an opposite direction, therebywithdrawing the rod 227 from the threaded passage 225 and easing theclamping pressure against the pins 31, 54.

Therefore, a number of apparatus and methods for quickly connecting aspoolgun power supply cable to a welding machine are provided. By usingone embodiment of the novel dual power pin connector to connect aspoolgun to a welding machine, the need for tools as in current weldingmachines is eliminated. Additionally, the dual power pin connectorprovides a semi-permanent mechanical and electrical connection betweenthe positive power weld terminal and the wire drive to ensure that thewelding machine will operate properly even in hostile workingconditions.

The present invention has been described in terms of the variousembodiments, and it should be appreciated that many equivalents,alternatives, variations, and modifications, aside from those expresslystated, are possible and within the scope of the invention. Therefore,the invention should not be limited to a particular describedembodiment.

1. A method of modifying a welding machine to accept two or more weldingimplements simultaneously comprising the steps of: providing anelectrically conductive connector, the connector having at least a firstreceptacle for a welding implement, and a hand-operated clampingassembly; electrically coupling the electrically conductive connector toa welding power output terminal of the welding machine; and electricallycoupling the electrically conductive connector to a wire drive, the wiredrive having at least a second receptacle for the welding implement. 2.The method of claim 1, further comprising the steps of: inserting aspoolgun power pin within the at least a first receptacle; and securingthe power pin within the at least a first receptacle with the clampingassembly.
 3. The method of claim 1, wherein the wire drive is configuredto provide a consumable welding electrode to the welding implement toeffectuate a first welding-type process upon receiving a welding-typepower.
 4. The method of claim 1, wherein the hand-operated clampingassembly further comprises an at least partially threaded rod extendingthrough the at least a first receptacle.
 5. The method of claim 4,wherein the hand-operated clamping portion is coupled to the threadedrod such that effectuating the rod in a first direction diminishes a gapdefined by the slot and presses the clamping portion against the powerpin retained within the at least a first receptacle.
 6. The method ofclaim 4, further comprising a hand-operated knob coupled to the at leastpartially threaded rod.